Low endoscopy completion rates are a major problem nationwide and in the VA. For clinics, delays or failure to complete exams can cause clinic inefficiencies, such as increased wait times for needed procedures, lost capacity, and increased costs. For patients, delays reduce the chance for recommended timely screening consistent with practice guidelines and for diagnostic tests, can cause significant anxiety, delayed treatment and possibly poorer prognosis. This study tests whether an Interactive Voice Response (IVR) messaging system is equally effective in motivating patients to complete a flexible sigmoidoscopy or colonoscopy as usual clinical care practices, which include reminder phone calls from clinic nurses. This is the first study to evaluate the use of IVR for endoscopy completion and the first to compare it to the effectiveness of phone calls from nurses prior to an endoscopy appointment.